Gear pump



Dec. 27, 1921.

J. 5. MYERS GEAR PUMP Filed Nov. 19, 1924 33heets-Sheet 1 1, I I 36 e r 9 I5. MYERS INVENTOR ATTORN EY wiTuEssE J. S. MYERS GEAR PUMP Dec. 27, 1927; 1,654,048

Filed NOV. 19, 1924 3 Sheets-Sheet 2 IS.I1YERS WITN I I INVENTOR ATTORNEY Dec 27, 1927.

J. 5. MYERS GEAR PUMP Filed Nov. 19. 1924 3 Sheets- Sheep 3 J. S. H YERS lNVENT ORV ATTORNEY I. m .1 flaw/A Patented Dec. 27, 1927.

UNITED STATES PATENT OFFICE.

JOHN S. MYERS, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSE ELECTRIC & MANUFACTURING GOMPAN Y, A CORPORATION OF PENNSYLVANIA.

GEAR PUMP.

Application flledltovember 19, 1924. Serial No. 750,806.

My invention relates to gear pumps and in particular to that form of gear pump in which a worm is employed to cooperate with the gear.

In the ordinary form of gear pump in which gears, meshing with each other, are employed, there is a loss due to the facts that the fluid to be pumped is trapped between the teeth of the gears and must be forced out through comparatively small openings, thus producing a back-pressure and that fluid is prevented from properly entering on the suction side when the teeth begin to disengage,-thus producing a partial vacuum. These factors reduce the efliciency of the pump and are prevented in my device by the use of a worm as a barrier to prevent the translation of liquid completely around the worm gear. The worm engages the gear with a sliding contact and no liquid is trapped between the teeth of the worm gear and worm, but the fluid is swept out, and on the suction side the fluid is admitted gradually to the gear.

One of the objects of my invention is to provide a pump in which the use of check and other valves is dispensed with, and in whichall passages for the liquid are relatively large, unimpeded by valves, and have as few abrupt changes in the direction as possible so that the danger of clogging is re duced to a minimum, and which operate smoothly and with a low loss of power. A further object is to produce a pump in which no liquid is trapped between the gear and theworm or in which no partial vacuum is produced by the withdrawal of teeth from the tooth spaces not in communication with the supply. A still further object is to produce a device of the character described which shall be eflicient, simple in operation, easy of construction, and which permits ready assembly or disassembly.

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These and other objects of my invention will be apparent from thecfollowing description, having reference to the accompanying drawings in which Fig. 1 is a vertical section oil one preferred embodiment of my invention talren on the line I-ll of Fig. 2; Fi g. 2 is a horizontal section taken on the line Jill-ll of Fig. 1.; Fig. 3 is a sectional view similar to Fig. 1 but illustrating another embodiment of my invention; Fig. 4: is a horizontal section taken on line lV-l[V of l ig. 5, showing a still further embodiment of my invention; Fig. 5 is a vertical section taken on line V-V of Fig. 4; and Fig. 6 is a View similar to Fig. 1 showing a modification of a detail of my device.

Referring first to Figs. 1 and 2, I show a gear pump 10 comprising an upper casing 11, a lower casing 12, aworm 13, and four gears 14 completely surrounding the worm. The worm 13 is of a type commonly known as the Hindley worm, which is characterized by the fact that it is cut on a solid of such form that if any plane be taken through its 1on gitudinal axis. the intersections of the plane by the perimeter are arcs of the pitch circle of the gear wheel into which the worm is intended to work. The worm 13 is driven by a shaft 16 which is held against longitudinal movement by a thrust bearing 17. The

worm, in turn, drives worm gears 14, which are mounted on shafts 19 and which rotate in the direction shown by the arrows in Fig. 1. The shafts 19 rest in semi-cylindrical recesses 21 in the upper and lower casings 11 and 12. The casings are held together by bolts 23. passing through lugs 24 on the casings 11 and 12. Should it be necessary, in order to secure a tight joint between the casings 11 and 12, the lugs could be extended completely around the edge of the casings as a flange or an additional number of lugs could be provided. The fluid to be pumped is supplied to the pump through a suitable conduit 27 communicating with the admission chamber 28 in the lower casing. The fluid is then entrained between the teeth 29 of the worm gears and the wall 31 ofthe casing and-is sweptaround by the teeth to the delivery chamber 33 which is in communication; with a discharge conduit 34. Due to the fact that the gears completely surround the worm only a very small amount of liquid leaks back to the chamber 28. Should any fluid seep around the shaft 16, it is collected at the chamber 36 and returned to chamber 28 through a pipe 89. If the fluid pumped is oil the thrust bearing 17' is placed in the chamber 36 as shown in Fig. 6.

in Fig. 3 I show a modification oi my pump in which a straight worm is used. This permits the worm to be longer than is possible with a Hindl'ey worm, thereby per mitting the thrust to be talren up by a hearing 41. With this form of worm the bot-- tom portion is bored out to form a recess 42 into which the fluid flows and from which it is delivered to the worm gears 14 through openings 44. It is of course, understood that in this embodiment the worm is tiompletely surrounded by gears as shown in In Figs, 4 and 5, I show a further modification of my invention. In this form the fluid is prope led by the worm 13 instead of by the gear, the gear 51 serving as a traveling barrier or gate. The worm 13' is of thehour glass or Hindley type, similar to the worm 13 of Fig. 1. The gear 51 will operate in the direction shownby the arrow in Fig. 5 which is the opposite direction to that in which the gears 14 of Fig. l'operate. This embodiment is less efiiclent than the precedim embodiments due to the factthat some oil willbe carried back between the gear 51 and the casing 11' and 12'. However, by making this worm gear relatively thin this amount is greatl reduced. In this form ofiny device, the uid enters .at'27', flows upwardly into the chamber 5 28' and is forced upwardly by the worm 13' from whence it is collected in the chamber 33 anddelivered to the discharge conduit 3.4".

While my invention is capable of wide application, I have found it particularly adapted for use as an oil pump in supplying fluid under pressure for lubrlcation and to fluid-pressure actuated governors -for rotating devices such, for example, as steam turbines. Furthermore, by applying fluid under pressure to the suction of the pump,

the fluid will cause a rotation of the gears and the device will operate as a fluid motor, power being delivered to the shaft of the worm or to one or all of the shafts of the worm wheels.

Although I have illustrated four worm wheels a lesser or greater number may be used, the object being to embrace the complete circumference of the worm.

While I have shown m invention in several forms, it will be 0 vious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications, without departing from the spirit thereof, and I desire, therefore that only such limitations shall be placed thereupon as are imposed by the prior art, or as are specifically set forth in the appended claims.

What I claim is:

1. In a fluid translating device, the combination of a worm, and gears meshing with the worm and having laterally abutting teeth, said teeth being arranged to completely encompass the worm.

2. In a fluid translating device, the combination of a. worm, and gears meshing with the worm and having their lateral edges beveled substantially on radii of the worm, the beveled edges being juxtaposed substantially in worln'ng contact.

In testimony whereof, I have hereunto subscribed my name this twelfth day of November, 1924.

-* JOHN S. MYERS. 

